The Brazil defender was given the domestic ban for an incident with official Christian Fischer during a pre-season friendly with Fortuna Dusseldorf.
Today Fifa applied the suspension worldwide, meaning Luisao will miss four Champions League fixtures.
Even without their skipper, Benfica coach Jorge Jesus believes his side can make a strong start in a group which also includes Barcelona and Spartak Moscow.
"We are very confident," Jesus said. "We are prepared for all conditions. The fact this has happened to Luisao is important, but we have other players.
"It's important to note that we focus on the game. All players have the same importance. My concern is the opposition, missing players is a secondary concern.
"We have conditions to use different players in different circum-stances to adapt to the game. We've worked on a strategy to match any team, be that Barcelona or any other team.
"The last three years Benfica have been in the Champions League. We're prepared for this match and we want to try to achieve a good result."
Celtic have suffered just two defeats in 18 home fixtures in the Champions League, but Neil Lennon's side enter the match with eight points from their opening five league games.
Celtic's worst start to the season since 1998/99 included a 2-1 loss at St Johnstone on Saturday. Jesus played down the significance of that result.
"It is normal for all teams in a game before the Champions League to be thinking more about the next big game," Jesus added.
